Shanaka sustained a thigh muscle injury in Tuesday's six-wicket loss to Pakistan and will need three weeks to recover, with Chamika Karunaratne replacing him in the Sri Lanka squad.

Mendis is among the tournament's top scorers with 198 runs in two games and his first match as captain will be Monday's clash with Australia who are also without a win in the group stage.

"I am very happy to have the captaincy and I hope to play in the future in the same way as I have played so far, because I don't have anything to change," Mendis told reporters on Sunday.

"I've had previous experience as a captain. I've also held the position of captain in practice matches here.

"Speaking about my batting, I aim to maintain this level of performance. I prefer playing in a manner that aligns with the team's requirements."

Mendis said Sri Lanka would miss all-rounder Shanaka, describing his absence as a "significant disadvantage".

"As a team, we deeply regret his absence. Moreover, when we previously lost Wanidu Hasaranga, we made an addition to the team to compensate for his absence," Mendis said.